2018 Dodge Ram 1500 Eco-Diesel Engine. 2018 Dodge Ram 1500 beneath the hood readies big surprises. In either case, it will probably be an active travel program. The first option is the 5.7-liter Hemi V8 engine with 395 hp and 410 lb-feet of torque. Hemi engine delivers strong torque, which is sent to the wheels and permit the rendering of duties.